Grinding machine



July 10, 1923. 1,461,514 J.A.BURN

GRINDING MACHINE Filed Jan. 25 1922 VINVENTOR James A .19 urns I I BY WITNESSES JAMES A. BURNS, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 8a MANUFACTURING COMPANY, A CQFPORATION OF PENNSYLVANIA.

GRINDING MACHINE.

Application filed January 25, 1922. Serial No. 531,626.

To all whom it may concern:

Be it known that I, JAMEs A. BURNS, a citizen of the United'States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Grinding Machines, of which the following is a specification.

My invention relates to grinding machines, more especially to chuck members for clamping the abrasive material employed therein.

It is among the objects of this invention to provide a grinding head" chuck member in which the abrasive material shall be secured to firmly hold it in position and to permit adjustment thereof as the working surface wears away;

It is another object of this invention to provide a chuck which shall be simple in construction, readily adjustable, and easily accessible for renewal of the abrasive material and which shall be capable of resistin the excessive stresses to which a high-spec rotating abrasive disk is subjected.

It has been customary, in the larger type of face grinding machines employed for facing large steel castings and the like, to

' employ abrasive inserts consisting of segmentary or block-shape pieces of carborundum or the like assembled in contact near the outer periphery on the working face of the grinding head or wheel. This is a more economical type of construction thancutilizing a solid disc in'view of the expense of forming and replacing a unitary abrasive facing disc. 7

Acommon prior type of insert-block construction' consisted 'of a suitably shaped groove in the workin face of the grinding j wheel for holding; t e blocks of abrasive material which were usually secured by common clamp bolts extending through a counter-bored recess provided in the work ing face of the abrasive material to bring the bolt-heads below the working surface of the abrasive blocks. These countersunk apertures produced very sharp corners around the face of the abrasive which were easily broken' and constituted a source of danger to the operator. Another disadvan-' tage was the splitting of the blocks which necessitated frequent replacement, as it was not only dangerous to operate underthese conditions but the blocks, having msuflicient support, became distorted and also were instrumental in the destruction of the adjacent blocks, around the periphery of the wheel. v

In my present invention I provide an im- Figure 1 is a fragmentary plan view of agrinding wheel constructed in accordance with this invention, and I Fig. 2 is a CI'OSSrSGCtlOIliLl view' thereof taken along the line II- II of Fig. 1.

The grinding head consists of a hub member 1 and a rim 2 having a pair of annular flanges 3 and 4, the flange 4 being provided with a depending flange 5 for engaging the hub 1 and being secured thereto by cap .bolt 6. The rim 2 is provided with chuck members comprising a plurality of clamp bolts 8 for mounting an adjusting nut 9. Sleeves 10 having tapered outer surfaces 11 and counterbores 12 are placed on the studs 8 to engage pressure blocks 13 having tapered concave surfaces 14 in engagement with the sleeves 10, and straight clamping surfaces 15 for engaging the abrasive blocks 16. r A plurality of such abrasive blocks 16 of suitable material, such as carborundum, or the like, having inclined sides 17 and curved outer surfaces 18 corresponding to the curvature of the flange 3, are inserted between the pressure blocks 13 and flange 3 and are secured therebetween by screwing the nuts 9 on the studs-8, which forces the :tapered sleeves 10 against the pressure 100 plates 13 until the blocks 16 are locked in position against the flange 3. The straight surfaces 15 of the clamping blocks 13 and the curved surfaces 18 of the flange 3 secure the abrasive blocks 13 in a wedge-like grip, me

making angular shifting of the abrasive material impossible. V

As the working face of the abrasive material is reduced in service, one ormore backing blocks or rings 19 may be inserted to 1m proved ,means for mounting the abrasive, Q

project the material beyond the face of the wheel. These backing rings 19 may be replaced by rings of increased dimensions to compensate for the wear of the blocks 16 until they are reduced to a minimum. This feature of taking up for the wear of the material could not be obtained with the old type of construction and is a decided advantage, in that the abrasive material may be more effectively utilized, thereby greatly reducing the expense of renewals.

It will be readily understood from the above description of my invention that disc grinding wheels formed in accordance therewith provide a safe, economical structure, which is simple to manipulate and readily adjustable to take up the wear of the grinding surface.

Although bodiment of my invention,

I.have described a specific emit will be obvious to those skilled in the art that various modi-- fications may be made in the details of construction thereof. For instance, the clamping blocks 13 may beof various shapes and may be provided With concave or convex engaging surfaces ofthe abrasive blocks 16, the clamping sleeves 10 may be replaced by square or other shaped wedges, the abrasive blocks 16 may be in spaced relation to each other, or they ma form a ring of contiguous segments. he edges 17 need not be inclined as shown in the drawing but may be radial to the center of the hub. These and other changes may be made in the details of construction of my grinding machine without departing from the principles herein set forth.

I claim as my invention:

1. The combination in a face disc grinding wheel, of a plurality of angular abrasive blocks disposed near .the outer periphery thereof and means for aligning and individually securing said blocks in their respective positions, said means comprising a plurality of screw chuck members mounted on said wheel, each including a clamping plate,

' said. blocks a stud bolt an adjusting nut and a tapered Wedge sleeve, said clamping late having a plane surface for engaging said abrasive material and a tapered concave surface in engagement with said. wedge sleeve.

2. The combination in a face disc grinding wheel comprising a central hub portion, having a double flanged rim mounted thereon, of a plurality of abrasive blocks in'contiguous alignment flanges and means for individually securing therein, said means comprising a of screw chuck members mounted plurality wheel, each including a clamping on said to correspond with the shape parallel annular flanges,

- clamping block,

disposed axially. within said.

of annular flanges in co-operati've alinement,

a plurality of abrasive blocks radially disposed against one of said flanges, a plurality of clamping blocks, engaging said abrasive blocks, and a plurality of tapered sleeves mounted on stud bolts between said clamping blocks and the other of said flanges, said sleeves being adapted to force said clamping blocks against the abrasive blocks.

4:. A face disc grinding wheel comprising a metallic wheel base provided with a pair of parallel annular flanges, a plurality of abrasive bocks, each having a surface corre sponding to the curvature of the inner surface of the outer flange-and having a straight surface adapted to engage a clamping block, a plurality of tapered sleeves engaging correspondingly tapered seating portions of said blocks and inner flange respectively, a plurality of stud bolts secured in said wheel base and extending through a counter-bored opening in said sleeves, and a plurality of threaded nut members adapted to be screwed on said bolts to engage the counterbored surface of said sleeves to wedge them between the co-operating engaging surfaces of the said clamping blocks and inner flange member.

5. A face disc grinding wheel comprising i a metallic wheel base provided with a pair of a spacing ring disosed between said flanges,'mounted in said wheel with one end resting against said ring, a plurality of abrasive blocks, each having a surface corresponding to the curvature of the inner surface of the outer flange and having a straight surface adapted to engage a a plurality of tapered sleeves engaging correspondingly tapered seating portions of said clamping blocks and inner flange respectively, a plurality of stud bolts secured in said wheel base and extending through a counterbored opening in said sleeves and a plurality of threaded nut members adapted to be screwed on said bolts to engage the counterbored surface of said sleeves to wedge them between the co-operating engagin surfaces of the said clamping blocks and inner flange member. Q In testimony whereof, I have hereunto subscribed my name this 23rd day of January, 1922.

' JAMES A. BuRNs. 

